Stop printing the database password

The report opened with the connection string it was about to work on, taken
straight from AIDND_DATABASE_URL. On the hosted deploy that string carries the
Neon password, so the first line of every run put a live credential into the
console — and from there into scrollback, a screenshot, or a pasted bug report.
Nothing in the output said it was there to notice.

It now prints scheme, user, host and database name. The query string goes whole:
sslmode is the only part worth reading, and some drivers accept a password
there as well.

631 green.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Tqgupw5CZGjSZrUTNUd4fW

plan/18-persona-and-memory-quality.md

@@ -4,7 +4,7 @@ Two changes, in order. Phase 1 gives the adventure a persona. Phase 2 uses it,
 along with the cast, to fix the memories. Phase 1 is worth shipping on its own;
 Phase 2 depends on it and is much smaller once it lands.
 
-**Both phases are built and green (629 backend tests). Phase 1 was driven in a
+**Both phases are built and green (631 backend tests). Phase 1 was driven in a
 browser (21/21 checks). Phase 2 was run end to end against a real model, as a
 controlled A/B on one story — see "Run with a real model". A bank written under
 the old prompt can be rewritten in place — see the last section.**